Vitamin D and SARS-CoV-2
Hoang Anh Nguyen
A novel enveloped β-coronavirus that first appeared in Wuhan, China has caused thousands of deaths across many nations due to pneumonia-like symptoms. This β-coronavirus, named SARS-CoV-2, shared nearly 70% similarity in genetic material with the renowned severe acute respiratory syndrome-related coronavirus (SARS-CoV-1). Like the SARS-CoV-1, there is still no specific treatment or prevention for the SARS-CoV-2. The likelihood that vitamin D may offer a possible preventive strategy on SARS-CoV-2 infection should be taken into account.
Growing evidence indicates that vitamin D is strongly related to pathogen elimination through increased expression of cathelicidin. The antimicrobial protein is also involved in the recruitment of cytokines and the differentiation of macrophages . Moreover, vitamin D may increase the production of regulatory T cells through the adaptive immune response. Randomised controlled trials in healthy adults consistently demonstrated that a significant reduction in respiratory tract infections was confirmed among those daily taking vitamin D supplementation, as compared with the controls . A meta-analysis of nine studies conducted by Laplana et al. confirmed that vitamin D may inhibit enveloped viruses . Additionally, inadequate vitamin D levels in the elderly are associated with a weakened innate immune activity . There is a significant association between the SARS-CoV-2 and the aged, particularly those more than 50 years old . Notably, a recent study by Wei and colleagues demonstrated that 70.3% of older adults in China were defined as vitamin D deficient .
Genetic variants of the vitamin D receptor (DR) should be taken into consideration in vitamin D status and its antimicrobial therapy in specific populations. Vitamin D is referred to as an antimicrobial strategy for Mycobacterium tuberculosis, but the outcome is deemed controversial. As mentioned earlier, vitamin D may regulate activation of macrophages by binding to their DRs. Once macrophages activated, they may intracellularly produce cathelicidin against M. tuberculosis . It is argued that DR variants such as rs2228570, rs1544410 and rs731236 might be involved in individual susceptibility to M. tuberculosis . Moreover, DR gene polymorphism also affects the effectiveness of vitamin D consumption .
Thus, an association between vitamin D level and COVID-19, particularly among senior adults, should be studied. Additionally, to optimise vitamin D’s effectiveness, the role of DR variants in different populations need to be further addressed.
Hoang Anh Nguyen, Faculty of Health Sciences and Sport, University of Stirling, United Kingdom
- Hewison M. Vitamin D and the immune system: new perspectives on an old theme. Endocrinol Metab Clin North Am. 2010;39(2):365–79. doi:https://doi.org/10.1016/j.ecl.2010.02.010. PubMed
- Bergman P, Lindh AU, Björkhem-Bergman L, Lindh JD. Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. PLoS One. 2013;8(6):e65835. doi:https://doi.org/10.1371/journal.pone.0065835. PubMed
- Laplana M, Royo JL, Fibla J, Vitamin D. Vitamin D Receptor polymorphisms and risk of enveloped virus infection: A meta-analysis. Gene. 2018;678:384–94. doi:https://doi.org/10.1016/j.gene.2018.08.017. PubMed
- Alvarez-Rodriguez L, Lopez-Hoyos M, Garcia-Unzueta M, Amado JA, Cacho PM, Martinez-Taboada VM. Age and low levels of circulating vitamin D are associated with impaired innate immune function. J Leukoc Biol. 2012;91(5):829–38. doi:https://doi.org/10.1189/jlb.1011523. PubMed
- Gralinski LE, Menachery VD. Return of the Coronavirus: 2019-nCoV. Viruses. 2020;12(2):135. doi:https://doi.org/10.3390/v12020135. PubMed
- Wei J, Zhu A, Ji JS. A Comparison Study of Vitamin D Deficiency among Older Adults in China and the United States. Sci Rep. 2019;9(1):19713. doi:https://doi.org/10.1038/s41598-019-56297-y. PubMed
- Vanherwegen AS, Gysemans C, Mathieu C. Regulation of immune function by vitamin D and its use in diseases of immunity. Endocrinol Metab Clin North Am. 2017;46(4):1061–94. doi:https://doi.org/10.1016/j.ecl.2017.07.010. PubMed
- Wang Y, Li HJ. A meta-analysis on associations between vitamin D receptor genetic variants and tuberculosis. Microb Pathog. 2019;130(130):59–64. doi:https://doi.org/10.1016/j.micpath.2019.02.027. PubMed
- Martineau AR, Timms PM, Bothamley GH, Hanifa Y, Islam K, Claxton AP, et al. High-dose vitamin D(3) during intensive-phase antimicrobial treatment of pulmonary tuberculosis: a double-blind randomised controlled trial. Lancet. 2011;377(9761):242–50. doi:https://doi.org/10.1016/S0140-6736(10)61889-2. PubMed